This “people detector” with pyroelectric sensor was found in the April 1991 issue of Radio Electronics magazine. The circuit is based on an LM324 and a sensor from that time.
This 555-based circuit was obtained from the 1995 Encyclopedia of Electronic Circuits volume 5. It...
This 1992 circuit was designed to operate with the CB16766E circuit auto alarm. The circuit...
This simple 2004 circuit uses a common sensor used in television and other equipment. It checks...